Automatic telephone-exchange system.



} Wi/fn eases /n ve/r'r'o r.-

A a. SPERRY.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED SEPT. n. 1915 Patented July 17, 1917.

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UNITED STATES PATENT OFFICE.

ARTHUR BRUGE- SPEBRY, OI NEW" YQRK; *N. Y., A-SSIGNOB, BY MES'NE ASS IGr'ltlillllllflTS, T0 WESTERN ELETRIC'COMPANY, INCORPORATED, 'A' GORPORATION"OF" NEW YORK.

asp e'e'ificationpf LettersPatent.

-Patented'Jn-1y- 17, 1,9137.

[0 all whom it may concern.

Be it ,known th-at l, An'rnnn 'BRUQE SPB R a citizen of 'the Unitegl ,States re siding. at New York, n the .co'untyof New York and Stateof. New York',,have invented certain new and usefullhnriroverhents in Automatic Telephone-Exchzinge ;Systems,, of which the following is a. full, clear, concise, and exactdescription.

'This invention relates. to. telephoneexchange systems, and particularly to auto matic tel ephone: exchange. systems.

It is glesirablaespeoially in aniautomatic telephone exchange system, afteraeall'has been extended and i-the oallingnndcztlled subscribers have beenrplaeed ,in communication with each other, that either-subscriber be notified when the other yhiangs 11p his ree'eiver and cannot befiurther. communicated with exceplrby a newcallingoperatiqn. ,To this ,engl t ere is pro'vided atihes final cQm ep etesi t h h ns ,ijng np ofqtheflrecelver of.,'either party, to

h lin andlw qr FThe. objectpfi-the invention, .threfore,. is. flt he provision of means for ,notifying. one ofithe, partiesgto va call ofthe hangingnp ofthereeeiverbymhe usy s 'gnahoven other party to said, call.

' The accompanying, drawing shows the .invention applied. to an.automaticatelephone syste w t muc te he y m sh w as ,is necessary .forran understanding ot-the invention. V

Assnrni'ng that subscriber ,A wishes to ':talk

with rsnhseriber'lB, and-,the cnllhas prog essed ,far. as. 'the lfin'al 'connectorgshown in the figure "through the intermediate switeh l0 (orswitches) ,line relayeil will ,b energ ed tram-battery, t ght nd n of-iline "elm lit-l n inducto 2+-r meg the Substation rap p arntlls of ,rsnhscriber, ,A,

over"line,cond1i 5tor J3, ithrongh theleft Winding of line relay {1,1, back. :to. battery, rg zing th lin relay-w ich mp an energizing cirQhithfQT- the islow acting relay .Wh in tum comp e e break point ifnthejcircnit .for'. the rotary magnet 15.

"The subscriber A new hctn'ates lthe ,im pnls e sending 'gle'tqice 16. to control ,the com ector. Each ,'1 terrnptionfnfItheiline .circhit te s 1 eaeu' nent mpuls in the tolle ing circnit vf It the rotary @magnet .15 ,fro'm battery," t hpcngh1the winding 'ofjeia idlrntary magnet; the arm v.ductor l7, armature and front contact. of

the slow-aeting relay 15L,,anclzarmature anol beck contact of line relay ,ll. EIIBEglZGdJ in multiple with the rotzirymagnet l 5rissan escape magnet relay 18, which operates over a circuit from battery, vwinding of -.sai-d. .relay 1 8 conductor 19, ;armature and- .bn,ck eontaetofia slow-acting relay 20,,eonduct0r 21,,conch1etor'1f7, armature, and front content of slow-aetingrelay :14, and arrnature and back, contact of line relay 11l t0 -gr0un(1.

The energization of the escapemegnet relay 18 completes a. circuit. from battery through theiescape magnet 22,,armatnre and back, contact, of release magnet; 23, conductor 24, contact, 2541\nd armature of escape mag- .n'et relay. 18, conductor 26,,arm5 ofthesigle switch, and,- right-hand: armature iandlbaek eontacts ,of relay .20 ,and bank-bridge relay conductor 28 1 and immature-an i; back 'cn'ntact h of generator control 7 relay 1 29 to r ndhe .:the necessary ,number ,of simplils s ,from the.- sending device, .16, havev heen sent ,over the ,line to select the ,tens, digit, (the line relay 11 is \maintained energized, resulting in a prolonged break in the circuit of both the rotary magnet. 15 and ,theiescape magnet relay: 18. The denergization .otthe. feseape magnet. relay 1s caus th op ning t t circuit for the escape magnetf22, wheren pon :thB side switch moves fromitsnorrnal posi- Itie 1 tqlpes n 2- The. islihscriher A new sends ,th units impulses ,from :the .impnlsensending, de vjiee 16, termit en y nergizing -t n r l y -1 1,, a's befnlge. hsithmside, switch {is inst e isecond position, ;the, ttentic al\,magnet A0, glS now intermittently energized;mot i glthe brushes 3.4,- 5 and-r36: ev the ter inele 0i suhscribershlines. As inrthe case whemthe ,tens impulses werelsent, the escape magnet relay 11B is ,held energized and-again thert-gi zes. ,the vesoa1pe magnet, 22 over (the Fcinenit 1hefnre traced.

When. ,the,necessaryl ,ml mher. nf impulses ,haveobeeir sent,t o pos tion the bmsh e 34,

If, "howeverj'the line to -whieh,g.0nneqtion mains energized; since contact spring 25 makes before the ground connection over conductor 26 is broken, and a circuit is maintained for the escape magnet through the busy relay 37 and its normal contact, the side switch arm 3 and the grounded terminal 31 with which the brush 34 is in contact. The busy relay thereupon closes for itself a locking circuit at its left-hand armature, and at its right-hand armature connecting the busy interrupter 38 to the line conductor 12 over the conductor 39.

In case the desired line is idle, the deenergization of the escape magnet 22 moves the side switch into the third position, whereupon the escape magnet 22 is again energized in a circuit from battery through the winding of said magnet, right-hand armature and back contact of release magnet 23, the arm 5 of the side switch in the third position thereof, right-hand armatures and back contacts of the slow-acting relay 20 and back-bridge relay 27, conductor 28 and armature of generator control relay 29 to ground. The escape magnet 22 closes a circuit from the ringing generator to the generator control relay 29, armature and front contact of escape magnet 22, conductor 41, arm 1 of the side switch in the third position thereof, brush 36, contact 33, out over the line through the apparatus of substation B, back to terminal 32, brush.35, arm 2 of the side switch in the third position thereof, to ground, thereby projecting ringing current over the line and causing the operation'of the signal bell at substation B.

Generator relay 29 does not operate on ringing current, but when the called subscriber removes his receiver from its switchhook, this relay operates, attracts its armature and breaks the circuit for the escape magnet 22, whereupon the side switch moves from the third into the fourth position. In the fourth position of the side switch, the subscribers are connected for conversation, and a circuit is closed from battery through right winding of back-bridge relay 27 out over the line to the substation B, back through the left winding of back-bridge rel'ay 27 to battery, energizing said relay, which attracts its armatures and closes at its ri ht armature and front contact a circuit 'or slow-acting relay 20 from battery over the conductor 28 and the armature of control relay generator 29 to ground;

Should either A or B hang'up his receiver at the termination of the conversation, it

is desirable that the 'reinainin g subscriber beiiiformed of such hanging up so 'he'm'ay know thatthe party who hangs up first cannot be again reached unless the calling operation' is repeated.

Assuming that subscriber B hangs up his receiver first, this'caus'es a break iiithe ener- 'a locking circuit f0 1310118 for conversation,

gizing circuit of the back-bridge relay 27 which deenergizes, breaking V at its right armature and front contact the circuit for the slow-acting relay 20, which in turn de energizes, establishing a circuit from battery through the escape magnet 22, right armature and back contact of release magnet 23, conductor 24, contact 25, winding of busy relay 37 conductor 42, conductor 43, arm 5 of the side switch in the fourth position thereof, right armatures and back contacts of the slow-acting relay 20 and back-bridge relay 27, conductor 28, and back contact and armature of generator control relay 29 to 7 ground, energizing the busy relay 37. The

busy relay 37 is thereupon energized, closing a locking circuit for itself at its left armature, and connecting the busy interrupter 38 to the line wire 12 at its right armature and front contact. The subscriber B having already hung up, is out of circuit. Subscriber A, however, being on the line, the busy signal from the interrupter 38 will be projected over the line through his substation apparatus, and he will be notified thereby of the hanging up of the receiver by subscriber B.

If subscriber A hangs up first, the line re lay 11 is deenergized, as in the case of the back-bridge relay 27, by subscriber B. The relay 14 being slow-acting is not immediately deenergized, and a momentary circuit is closed from battery through the winding of escape magnet 22, right armature and back contact of release magnet 23, conductor 24, contact 25, winding of busy relay 37, conductor 42, conductor 45, arm 4 of the side switch in the fourth position thereof, conductor 17, armature and front contact of slow-acting relay 14 and armature and back contact of line relay 11 to ground, energiz ing as beforethe busy relay 37 which closes r itself at its left armature and connectsv the busy interrupter 38 to the line conductor 12, in this case proectmg the busy signal to the subscriber remaining on the line; that is, to subscriber B.

What is claimed is:

1. In an automatic telephone exchange system, two subscribers stations, automatic means for connecting said subscribers star and signaling apparatus intermediate thereto operated by achange in the condition of the apparatus at either station for notifying the other station of said changed condition.

2. In an automatic telephone exchange system, a plurality of subscribers stations, automatic means for connecting any two of said stations for conversationpand signaling apparatus operated by a change inthe con dition of the apparatus of either of the stations connected for conversation for notifying the other station of such changed coiidition'.

, apparatus at the central ofiice adapted to project signaling current to either of said stations, arelay for each of the subscribers? stations and under the control thereof 10- cated at the centralofiice, and a'switoliing @device operatedby either of said relays for connecting said apparatus with, the line,

'. whereby said signaling current is projected to the remaining station.

4. Ina telephone exchange system, a central office, a plurality of subscribers stations, automatic means for connecting any i 1 two of said stations for conversation, ap-' paratus adapted to project signaling current to either of said two subscribers stations,

and a switching deviceunder the control of either subscribers station for connecting said; apparatus. with the remaining subscribers station.

i 5. In a telephone exchange system, a central office, a plurality ofsubscribers, stations, automatic means for connecting any two ,ofsaid stations for conversation, ap-- paratus adapted to project signaling. current to either vof said two stations from said central oflice,'a switching device at the acn wtral office foi-"connecting said signaling curjrentwith eitherstation and adapted to be 1; operated by either subscriber whereby said Copies of this patent may be obtained tor five cents each, by addressing the Commissioner of I Patents,

signaling current is projected to the other station; v 1 i "6. Ina telephone exchange system, a plu- I condition.

rality of subscribersstations, central oflice automatic means for connecting any two of said stations for conversation andapparatus located atthe central office operated 1 #40" upon disconnection of the telephone at either of the stations connected for conversation for signaling the other :statioiiiof suchdisc'onnection. v

' 7. In. an automatic telephone exchange j 6 central office selective means for connecting said stations for conversation," a source" of signaling current at the central ofiice, auto- 1113,1310 means for connecting said source in a j 50 system, a plurality offsubscribersr stations,

circuitwith a calling station upon test by said selective switching means of a busy wantedstation, and means for renderingeffective said connecting means so as to con nect said source in circuit with either of the two stations, when connected for 'conversa tion, upon disconnection of the telephone apparatus at the other station.

. 8; In an automatic telephone exchange a j i system, two subscribers stations, automatic means for connecting said subscribers sta tions for conversation, apparatus intermedi so} i ate thereto operated by a change in the con f dition of the apparatus at the calling sta-' tion connected for conversation for notify-J ing the called station of the said changed In witness whereof, I hereunto subscribe my name this 8th day of September A. D.

' ARTHUR BRUCE SPERR Y Washington, 1). c." 

